The invention relates to a fuel for compression-ignition engines, i.e. a diesel fuel.
Mixtures of monooxymethylene dimethylether (dimethoxymethane) and diesel are known as fuels for diesel engines from SAE TECHNICAL PAPER SERIES, 1999-01-1508, pages 1 to 13. The addition of diesel fuel is used here to increase the cetane number of the mono oxymethylene dimethyl ether from 29 to values of above 40. The addition of diesel fuel, however, leads to an undesired soot emission. On the other hand, it is not possible to operate a diesel engine with pure monooxymethylene dimethylether as the latter has too low a cetane number of 29. This results in the fact that a cold start is impossible and misfiring occurs during a part load operation.
The use of dioxymethylene dimethylether and trioxymethylene dimethyl ether/tetraoxymethylene dimethylether mixtures as an addition to diesel fuel is known from the technical motor journal MTZ, 72nd volume, page 198 to 202 (2011). The use of these ethers leads to a significant reduction in the soot emission but a particle filter is still necessary to satisfy the existing legal requirements. In addition to this there is the fact that these polyoxymethylene dimethylether mixtures can only be produced at great expense.